Authors:

Nikolai Kalugin(New Mexico Tech)

Lee Wickey(New Mexico Tech)

Vladimir Talanov(Solid State Measurements Inc.)

We investigated the effect of various gases (ambient air,
Nitrogen, Argon,
Helium, and Oxygen) on a probe-sample shear-force distance
control in
scanning probe microscopy. To quantitatively measure a change in the
probe-sample distance due to a gas effect we employed a
near-field scanning
probe microwave microscope [1], which provides for independent
measurement
of changes in the distance with 0.1 nm resolution. A heavily
doped Si wafer
was used as a sample. We found that while air and Oxygen yield
similar
probe-sample distance, Nitrogen, Argon, and Helium increase it by
1-3
nanometers. Using Argon we also observed a reduction in the
shear-force
noise from 0.5 nm down to 0.25 nm, which is an important factor
for making
quantitative measurements. The data suggest that the major
contribution into
shear force is the attractive Coulomb force due to localized
surface charges
and/or surface potential difference.
[1] V. V. Talanov, A. Scherz, R. L. Moreland, and A. R. Schwartz,
Appl.
Phys. Lett. \textbf{88}, 134106 (2006).

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.J15.11